Heffner began his career in law enforcement in 1985 as a patrolman in Normal. He moved to the Illinois State Police in 1989 where he worked in drug interdiction, internal affairs, labor relations and counterterrorism, and also supervised a narcotics task force comprised of several agencies. Heffner retired from the state police in 2010 as a lieutenant colonel and was hired as Bloomington police chief in 2013.

The Senate Judiciary Committee must approve the nomination before sending it to the full Senate.